If you can boot into Windows 7, then you can copy your files by simply dragging the active User folders onto an External HD you connnect, a DVD you format for live storage, or send them over your network to another computer.
If you cannot now boot into Windows 7, copy out your files using the Windows 7 DVD Repair console or Repair CD: Copy & Paste - in Windows Recovery Console System Repair Disc - Create
After your files are safely retrieved, see if you can repair your HD using the maker's diag/repair full CD Scan: Hard Drive Diagnostics Tools and Utilities (Storage)
Then run Disk Check
Sometimes on a badly impaired HD you'll need to run one of the tests above in order to get the other one to work. And you may need to run both several times to complete the repairs. You should know by then whether the drive is reparable or needs to be replaced immediately. If it is reparable, test it routinely to see if it develops problems again.